Compact recording instrument



Aug. 11, 1970 l K. vGTuN 3,524,194

' COMPACT RECORDING INSTRUMENT Filed June 4, 1968 4 Sheets-Sheet 1 vs/vrop X or/ V'an w Aug. 11,' 1970 v 3,524,194

COMPACT RECORDING INSTRUMENT Filed June 4, 1968 4 Shoots-Shoot 5 wm/x rop Kw Voarz //v 8- 11, 1970 K. VGTLl-N 3,

COMPACT RECORDING INSTRUMENT 8, 52min United States Patent 3,524,194 COMPACT RECORDING INSTRUMENT Karl Viigtlin, Villingen, Germany, assignor to Kienzle Apparate G.m.b.H., Villingen, Black Forest, Germany Filed June 4, 1968, Ser. No. 734,263

Claims priority, application Germany, June 6, 1967,

1,268,889 Int. Cl. Gtlld /32 US. Cl. 346-123 12 Claims ABSTRACT OF THE DISCLOSURE Recordings are made on a flexible circular recording sheet while the same is rotated by a clockwork on a curved support in a curved condition in which two diametrical peripheral points thereof are spaced a distance smaller than its diameter so that the transverse width of the support and its housing are smaller than the diameter of a standard recording sheet.

BACKGROUND OF THE INVENTION The present invention is particularly concerned with recording instruments of the type in which a clockwork rotates a recording sheet while recordings are made by the same under the control of measuring means, such as a speedometer by which the speed of a motor car is measured.

Instruments of this type are known which have a substantially cylindrical housing with a pot-shaped main housing part, a circular closure part on which the clockwork is mounted. The diameter of the circular closure part and of the cylindrical main part is substantially the same, and is determined by the diameter of a standard circular recording sheet. A certain standard size is desirable, since a reduction of the size of the recording sheet renders the recorded graphs diflicult to read and evaluate. Recording tachographs of this type are mounted either on the dashboard, or in the space below the same. While the larger dashboard of a bus or truck affords sufficient space, a recording tachograph of standard size cannot be built into the smaller dashboard of a passenger car and, in accordance with the prior art, the recording tachographs were placed in the space below the dashboard of a pas senger car. However, a recording instrument in this region of the car reduces the safety of the passengers and of the driver, and has the disadvantage that the speedometer of the recording instrument cannot be placed on the dashboard for inspection by the driver.

It has also been proposed to provide a recording tachograph with a prismatic housing in which the standard diagram sheet is rotated in a position located in a plane substantially perpendicular to the dashboard. However, this construction does not permit the indicator means of the speedometer to be located on the dashboard, and an independent speedometer is required in addition to the recording tachograph.

SUMMARY OF THE INVENTION It is one object of the invention to provide a recording tachograph including an indicating speedometer which can be mounted on the dashboard of a small motor car and has a cylindrical housing whose circular end portion is mounted on the dashboard and is provided with indicating means, indicating, for example, speed, distances travelled, and the time of the day.

Another object of the invention is to provide a recording tachograph designed for recording on a standard recording sheet, but having a diameter and transverse width smaller than the diameter of the standard recording sheet.

Another object of the invention is to provide a com- 3,524,194 Patented Aug. 11, 1970 pact recording instrument whose transverse width is less than the maximum dimension of a standard recording sheet. A related object of the invention is to provide a recording tachograph whose transverse width is sufliciently small for mounting of the tachograph on the dash board of a small car, while a standard recording sheet having a diameter greater than the transverse width of the housing is used for the recordings of the speed variations of the car.

Another object of the invention is to provide a compact recording instrument which does not require special small recording sheets.

In accordance with the invention, and with these objects in view, recordings are made on a recording sheet while the same is in a curved condition.

One embodiment of the invention comprises housing means having in a transverse plane a given width, for example the diameter of a cylindrical housing; a flexible recording sheet having between two diametrical peripheral points a transverse extension greater than the given width of the housing means, for example a greater diameter; support means for supporting the recording sheet in a curved condition in which the two diametrical peripheral points are spaced a distance smaller than the given width of the housing means; drive means, such as a clockwork, for rotating the recording sheet in the curved condition; and recording means for recording on the recording sheet and being, for example, operated by speed-responsive means if the instrument is mounted on the dashboard of a motor car.

Due to the curved condition of the recording sheet, its maximum transverse extension is less than its diameter, and consequently recordings can be made on a standard recording sheet in a housing having a transverse width smaller than the diameter of a standard recording sheet.

Preferably, the housing means include a main housing part mounted behind the dashboard, and a movable housing part located on the dashboard and being operable to open the housing for access to the recording sheet whose support is connected with the movable housing part.

In one embodiment of the invention, the movable housing part, and the support of the recording sheet are mounted in the main housing part for rectilinear movement, and are operated like a drawer.

In another embodiment of the invention, the movable housing part is pivotally mounted on the main housing part and is connected by a linkage to the support of the recording sheet so that turning of the movable housing part to an open position causes movement of the support with the recording sheet out of the main housing part.

Indicating means are advantageously provided on the movable housing 'part. The recording means, which preferably include several recording elements for recording different measured values, are mounted in the main housing part and are in a recording position engaging the surface of the recording sheet when the movable housing part is closed.

It is advantageous to provide a lock on the movable housing part, and to render the recording elements inoperative when the lock is operated to open the movable housing part.

The recording sheet is bent about one diametrical line. In one embodiment of the invention, the recording elements are mounted for angular movement and have points moving along a circular path transverse to the straight bending line of recording sheet so as to remain in contact with the surface of the recording sheet.

In another embodiment of the invention, the recording elements are guided for rectilinear movement and have points engaging the surface of the recording sheet along the straight bending line.

The bent and curved condition of the recording sheet is obtained by holding the flexible recording sheet onto a suitably curved surface of a support so that the flexible recording sheet slidingly abuts the surface of the support while being rotated to place different portions thereof under the recording elements.

The novel features which are considered as characteristic of the invention are set forth in particular in the append-ed claims. The invention, itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view illustrating an embodiment of the invention in which a movable housing part carrying the recording sheet is pulled out like a drawer;

FIG. 2 is a longitudinal sectional view illustrating the embodiment of FIG. 1;

FIG. 3 is a sectional view taken on line III-III;

FIG. 4 is a fragmentary elevation illustrating a detail of FIG. 3 in another operational position; and

FIG. 5 is a longitudinal sectional view illustrating another embodiment of the invention provided with a tiltable cover part carrying a speedometer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to the embodiment illustrated in FIGS. 1-4, the perspective view of FIG. 1 shows the recording instrument 1 in an open position in which a drawer-like movable housing part 3 has been pulled out of the cylindrical main housing part 2. Movable housing part 3 is connected with a part-cylindrical support 4 having an inner part-cylindrical support surface 5 on which a recording sheet 6 abuts in a correspondingly curved condition. The movable housing part 3 has an arcuate front portion 7 carrying the dial and pointers 8 of a clockwork, a signal lamp 10 indicating excessive speed, and a lock 9 by which the movable housing part 3 can be locked to the housing part 2 in the closed condition of the housing shown in FIG. 2. The speedometer dial 11, the speedometer pointer 12, and the mileage indicator 13 are mounted on a dashboard portion 2a of main housing part 2. The arcuate portion 7 fits into a corresponding recess in the main housing portion 2a.

As best seen in FIGS. 2 and 3, the curved support 4 has an abutment on which an elongated clockwork casing 14 is mounted. Two guide pins 15 and 16 project transversely from clockwork casing 14 and are located in guideways 17 and 18 in inwardly projecting ribs of main housing part 2. The clockwork in casing 14 drives by the shaft 19 the minute hand 20, and by a tubular shaft 21 the hour hand 22 of clock 8.

The clockwork is also connected by a shaft, not shown, to a circular attaching disk 23 which is pressed by a holding nut 24 against the circular diagram sheet 6 so that the same is held against the part-cylindrical surface 5 of support 4 and assumes a corresponding curved condition in which it is rotated by drive means 23, 24 while in sliding contact with the part-cylindrical supporting surface 5 of support 4. One diametrical line of recording sheet 6 will always be in contact with the straight generatrix line 5a of support surface 5 in a longitudinal plane of symmetry, while a transverse diametrical line located in a transverse plan will be part-circular and have diametrical peripheral points 6a spaced in transverse direction a distance smaller than the diameter of the recording sheet 6, and of course also smaller than the diameter of housing part 2. Consequently, the diameter of the housing is smaller than the diameter of the used recording sheet 6, and if the same is a standard recording sheet, the diameter of the housing parts 2 is smaller than the diameter of a standard recording sheet.

In the embodiment of FIGS. l-4, the recording points 58, 60 and 66 of recording elements 57, 59 and 65 turn about a shaft 54 whose axis is parallel to the straight generatrix line 5a of part-circular support surface 5, and which axis is located in the center of the part-circular support surface 5 so that the recording points 58, 60 and 66 move along a circular path in contact with the part circular surface of recording sheet 6.

A flexible shaft, not shown, of conventional construction is driven from a part of the car moving at a speed proportional to the speed of the car. A prismatic coupling portion of the flexible shaft is inserted into the corresponding prismatic coupling recess 26a of an input shaft 26 which is mounted in bearings 27 and 28 supported in walls of main housing part 2. The flexible shaft, not shown, is held in the coupled position by a nut, not shown, screwed onto the threaded boss 25 of housing part 2.

Input shaft 26 carries a permanent magnet 29, which may consist of several individual permanent magnets, and rotates the same at a speed depending on the speed of the car in a bell-shaped armature 31 which is surrounded by a ring 32. The rotating permanent magnet 29 produces eddy currents in bell-shaped member 31 which is urged to follow rotation of permanent magnet 29, but is restrained by a spring 36 so that the angular position of bell-shaped member 31 represents the speed of shaft 26 and the speed at which the car travels. Bell-shaped member 31 of the speed-measuring device 30 is secured by a bushing 33 to the measuring shaft 34 which is mounted in a bearing 35 in input shaft 26 and in a bearing in a housing wall 2b. One end of spring 36 is secured to a fixed point of the housing, and the other end is secured to measuring shaft 34 so that spring 36 is tensioned when member 31 is angularly displaced.

A gear 37 on measuring shaft 34 meshes With a gear 38 secured to the pointer shaft 39 so that the angularly displaced position of pointer 12 represents the speed of the vehicle on the dial 11.

Input shaft 26 has a worm gear portion 43 meshing with a worm gear 44 on a shaft 45 which carries another worm gear 47 meshing with a worm gear 46 on a shaft 48 connected with a worm gear 49 which drives the register gear 42 of the lowest order of an odometer counter 13. A line of digits of the number wheels of the counter appears behind the rectangular window 41 in dial 11 of the speedometer as best seen in FIG. 1. Shaft 39 carries another gear 50 which meshes with a gear 52 secured to a transmission shaft 51 which is mounted in bearings of walls of main housing part 2. A bearing bail 53 has two legs supported for angular movement on transmission shaft 51, as best seen in FIGS. 3 and 4. A recording shaft 54 is mounted between the legs of member 53 and carries a gear 56 meshing with gear 55 on transmission shaft 51 in all angular positions of member 53.

The speed-dependent angular displacement of member 31 of the tachometer 30 is tarnsmitted by measuring shaft 34 and meshing gears 37, 38 to pointer shaft 39, and by meshing gears 50, 52 and 55, 56 to recording shaft 54 to which a recording element 57 is fixedly secured for angular movement therewith. The recording point 58 is resiliently mounted on recording element 57 in a manner illustrated for recording elements 59 and 65 in FIG. 3, and is normally in contact with the curved surface of recording sheet 6 due to the fact that the axis of measuring shaft 54 is located at the center of the part-cylindrical support surface 5 of support 4. The angular displacement of recording element 57 at the possible speeds is selected so that the recording point 58 cannot move beyond the points 6a of the recording sheet 7, or into contact with the attaching and holding means 23, 24 at the center of the recording sheet 6.

A second recording element 59 with a spring mounted recording point 60 is mounted on recording shaft 54 for free turining movement and is connected with a spring 61 secured to a housing part and urging recording element 59 to turn to a position in which a follower roller 62 on an arm of recording element 59 co-operates with heart-shaped cam 63 whose shaft carries a worm gear 73 meshing with a worm gear 72 on a shaft 71 carrying a worm gear 70 meshing with a worm gear 69 on shaft 48. Since shaft 48 is driven through shaft 45 and gears 46, 47 and 44, 43 from input shaft 26, the angular displacement of cam 63 represents the number of revolutions of shaft 26 and the travelled distance which is recorded by the recording point 60 of recording element 59 on the recording sheet 6.

A third recording element 65 carrying a spring mounted recording point 66 is also mounted on recording shaft 54 for free turning movement and is coupled with a vibratory pendulum 64 biassed by a spring 67. As long as the engine of the car operates, or the car is in motion, pendulum 64 vibrates between two end positions limited by stationary stops 68 so that recording point 66 records a beam-shaped zig-zag line on recording sheet 6, while complete immobility is indicated by a single line.

The movements of recording elements 57, 59 and 56 are substantially radial to the axis of rotation of recording sheet 6, and the recording points move parallel to the part-circular support surface 5, but due to the rotation of the recording sheet 6, circumferentially extending graphs are produced on recording sheet 6.

When the movable housing part 3 is pulled out from the position of FIG. 2 to the position of FIG. 1, clockwork casing 14 and support 4 move therewith, and consequently the recording points 58, 60 and '66 would make straight lines parallel to the generatrix 50 if remaining in contact with recording sheet 6.

The bail-shaped support 53 of shaft 54 is connected by link means 75, 76 with a lock 9, as shown in FIG. 4. When the lock is operated by a key, not shown, link 76 is turned, link 75 is displaced, and support 53 is turned about transmission shaft 51 from the position of FIG. 3 to the position of FIG. 4 in which the recording points 58, 60 and 66 are retracted together with recording elements 57, 59 and 65 to a position spaced from the surface of recording sheet 6 so that the same can be pulled out with the movable housing part 3 without being in contact with the recording points.

When the movable housing part 3 is returned to the normal position, for example after exchange of the recording sheet 6, turning of lock '9 will cause an angular displacement of support 53 so that recording points 58, 60 and 66 again engage the surface of the properly placed recording sheet 6. Instead of lock 9, a turntable bolt for securing the movable housing part 3 in the operative position may operate linkage 75, 76 and support 53.

As explained above, the recording means of the embodiment of FIGS. 1-4 move along a circular path along a correspondingly curved circular diametrical line of recording sheet 6, and are consequently mounted for angular movement on shaft 54. Due to the curved condition of recording sheet *6, the diametrical points 6a are spaced from each other a distance which is less than the diameter of recording sheet 6, and the circular cross-section of housing part 2 is only a little wider in transverse direction. In recording instruments according to the prior art using the same standard circular recording sheet, the recording sheet is placed and rotated in a plane perpendicular to the axis of the housing so that the transverse diameter and width of the housing must be greater than the diameter of the recording sheet. Consequently, the transverse width of a housing of a recording instrument according to the invention, can be substantially smaller than the transverse width and diameter of the housing of a recording instrument according to the prior art.

In the embodiment of FIGS. l-4, the recording sheet is bent about the straight generatrix line 5a which is parallel to the main axis of the cylindrical housing and to the axis of shaft 54.

In the embodiment of FIG. 5, the straight generatrix line 88a about which the recording sheet 88 is bent, extends at an angle of approximately 45 degrees to the longitudinal axis of the cylindrical housing part 77 and to a plane transverse to the axis of the housing.

A movable housing part 79 is mounted on a hinge means 78on the main housing part 77 for angular movement between the closed position shown in FIG. 5 and an open position. The front face of cover part 79 is recessed and covered by a transparent plate 80 behind which the dial 81 and the pointer 84 of a speedometer are arranged for observation. A bolt 85 holds cover part 79 in the illustrated closed position. Cover part 79 has bracket means 86 and 92. Bracket means 86 supports a shaft on which a curved support plate 87 for the recording sheet 88 is mounted for angular movement. A clockwork housing 89 is secured to support 87 and carries pins 94 sliding in slots 95 of links 93 pivotally connected with a shaft supported by bracket means 92. Support 87 carries a pair of guide pins 96 which in the closed position of the housing shown in FIG. 5, are located at the ends of the pair of guide ways 97 supported by housing part 77. Leaf springs 98 are mounted in guide ways 97 and block return movement of support 87 in the operative position shown in FIG. 5 by engaging blocks 96a.

Support 87 has a support surface 87 which is curved symmetrically to the straight line 88a and forms part of a conical surface.

Clockwork 89 drives an attaching means 90 to which recording sheet 88 is clamped by the holding nut 91 so that the recording sheet 88 slidingly abuts the curved supporting surface 87a of support 87 while rotated relative to the same.

A tachometric device including a permanent magnet 99, a bell-shaped eddy current member 100, a ring 101 and a spiral spring 102 is driven by an input shaft 103 rotating at a speed proportional to the speed of the travelling car so that the angular position of member represents the speed. Input shaft 103 rotates a worm gear 104 meshing with a worm gear 105 on a shaft 106 whose worm gear 107 drives a worm gear 108 on another shaft 109. A pair of gears 110 and 111 transmits the rotary motion of shaft 109 to a shaft 112 which drives by gear 113 a gear 114 on a shaft 115 driving a worm gear 116 by which the register gear 118 of the lowest order of an odometer 117 is driven so that the mileage is indicated by the number wheels of the odometer in window 82 in dial 81 of the speedometer. The shafts of the transmission between input shaft 103 and odometer 117 are mounted in bearings supported by the main housing part 77 and in walls and bearing brackets secured to the same.

The speed-representing angular displacement of member 101 of the tachometric device is transmitted by meastiring shaft 119 and a gear 120 thereon which meshes with a rack bar on a slide 121 which moves parallel to the straight generatrix line 88a of the supporting surface of support 87. Recording slide 121 is mounted for straight movement on guide rods 122 secured to housing part 77, and carries a recording element 103 on which a recording point 124 is resiliently mounted.

The transmission of the angular movement of the measuring shaft 119 to the speed indicator pointer 84 is effected through a pulley and rope transmission including a pulley 125 secured to the measuring shaft 119, the endless rope 126, deflecting pulleys 127 and 128, and pulley 129 secured to shaft 83 of pointer 84 and passing through a wall of the movable housing part 79.

Another slide 130 is mounted for straight movement on guide rods 122 and carries a recording element 139 with a resiliently mounted recording point 132. A spring 133 biases slide 130 to move to a position in which a cam follower roller 134 thereon engages the peripheral track of a heart-shaped cam 135 carried by shaft 109. Since the position of shaft 109 and cam 135 is derived from the number of revolutions of shaft 103, the position of the recording element 131 with recording point 132 represents the distance the car has travelled which is also recorded on the curved recording sheet 88 during rotation of the same.

The recording points 132 and 124 move in radial direction of the circular standard recording sheet 88 along the straight bending line of the recording sheet due to the fact that respective slides are guided on guide rods 122 which are parallel to the straight generatrix line 88 of supporting surface 87a.

When the movable cover part 79 is opened and pivoted to a lower position about hinge shaft 78, support 87 with recording sheet 88 moves away from the recording points 132 and 124 while guide pins 96 depress leaf springs 89 and move in guide ways 97. When pins 96 arrive in a position located outside of guide ways 97, the support 87 is further moved out of the main housing part 77 by the angular movement of cover part 79 so that the recording sheet 88 becomes accessible. When the cover part 79 is moved back to the illustrated closed position, guide pins 96 enter the guide ways 97 when cover part 79 is almost in the closed position, and thus are guided by the guide ways 97 to the illustrated position in which holding springs 98 arrest support 87 in the plane in which the recording points 132 and 124 operate. Due to the spring mounting of recording points 132 and 124, no particular accuracy is required since recording points 132 and 124 are slightly displaced against the action of the springs mounting the same when engaging the recording sheet 88 on support 87. The radial motion of the recording points 132 and 124 produces graphs extending in circumferential direction of the rotating recording sheet 88. Although the recording sheet 88 rotates in curved condition, the radial strip located at any time on the straight generatrix line 88a of support 87 is straight so that the recording points can clearly record a graph on the recording feet.

Since in the constructions of the present invention, the transverse width, and the diameter of the housing do not have to be determined by the diameter of the standard recording sheet, a housing of small diameter can be used which is easily mounted on the dashboard and does not interfere with the convenience or safety of the passenger of the car.

While the advantages of the invention are particularly apparent when cylindrical housings have circular parts on the dashboard are used, it will be understood that the reduction of the transverse width of differently arranged housings will also result in more compact instruments. For example, the recording instrument disclosed in the German Pat. 1,201,075, or in my co-pending application Ser. No. 608,396, now Pat. No. 3,434,152, can be reduced in size by applying the principle of the present invention if little space is available in the region behind and on the dashboard.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of recording instruments differing from the types described above.

While the invention has been illustrated and described as embodied in a compact recording tachograph for mounting on the dashboard of a car and having means for recording on a curved recording sheet so that the transverse width of the instrument is reduced, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

I claim:

1. Recording instrument, comprising, in combination, housing means having a given width in a transverse plane; a. flexible circular recording sheet having a diameter greater than said transverse width; support means mounted in said housing means engaging the rear face of said recording sheet and supporting said recording sheet in a curved condition bent about a straight line into a cylindrical shape having a central axis parallel with said line so that said recording sheet has a concave front face and two curved portions extending in opposite directions from said straight line and having at the extremities thereof two diametrical peripheral points spaced in a direction parallel to said transverse plane a distance smaller than said given width; recording means in said housing means for recording on said concave front face of said recording sheet; mounting means for mounting said recording means for angular recording movements about said central axis in radial direction of said recording sheet and in a plane perpendicular to said line; and drive means for rotating said recording sheet about the center thereof whereby recordings can be made on a standard recording sheet in a housing means having a width smaller than the diameter of the standard recording sheet.

2. Recording instrument as claimed in claim 1 wherein said mounting means include a shaft having said central axis and mounted in said housing means; and wherein said recording means are mounted on said shaft for angular recording movements about said central axis.

3. Recording instrument as claimed in claim 1 wherein said support means has a curved cylindrical supporting surface slidingly supporting the rear face of said recording sheet; and comprising holding means for holding said recording sheet in sliding contact with said curved supporting surface so that said recording sheet is bent into said curved condition.

4. Recording instrument as claimed in claim 3 wherein said curved supporting surface is bent about a straight line and has two curved surface portions extending in opposite directions from said straight line and supporting at the extremities thereof said diametrical peripheral points of said recording sheet.

5. Recording instrument as claimed in claim 4 comprising means mounting said support means in said housing means in a position in which said line of said supporting surface is perpendicular to said transverse plane.

6. Recording instrument as claimed in claim 1 wherein said housing means includes a main housing part and a movable housing part; and wherein said support means is normally located in said main housing part and is connected with said movable housing part for movement with the same to a position located at least partly outside of said housing means for exchange of said recording sheet.

7. Recording instrument as claimed in claim 6 wherein said movable housing part is slidingly mounted on said main housing part for straight movement with said support means and said recording sheet.

8. Recording instrument as claimed in claim 1 wherein said housing means includes a main housing part, and a movable housing part having an open position and a closed position, and connected with said support means for moving the same to a position in which said recording sheet is accessible for exchange when said housing part is moved to said open position; said main housing part having guide means for guiding during movement of said movable housing part to said closed position, said support means with said recording sheet to a position in which said recording means co-operate with said recording sheet.

9. Recording instrument as claimed in claim 1 comprising a clock Work mounted in said housing means for driving said drive means and thereby rotating said recording sheet; and speed-measuring means mounted in said housing means for operating said recording means whereby the recordings on said sheet graphically indicate speeds at different times.

10. Recording instrument as claimed in claim 1 comprising control means connected with said mounting means for moving the same with said recording means between a normal recording position and an inoperative position in which said recording means are spaced from said recording sheet; and wherein said housing means include a movable housing part having an open position for access to said recording sheet, and a stationary housing part; and lock means for said movable housing part connected with said control means for moving said mounting means to said inoperative position when said movable housingpart is opened by said lock means, and for holding said recording means in said recording position when said movable housing part is locked.

11. Recording instrument, comprising, in combination, housing means having a given Width in a transverse plane; a flexible circular recording sheet having a diameter greater than said transverse width; support means mounted in said housing means engaging the rear face of said recording sheet and supporting said recording sheet in a curved condition bent about a straight line into a cylindrical shape having a central axis parallel with said line so that said recording sheet has a concave front face and two curved portions extending in opposite directions from said straight line and having at the extremities thereof two diametrical peripheral points spaced in a direction parallel to said transverse plane a distance smaller than said given width; recording means in said housing means for recording on said concave front face of said recording sheet; mounting means including a shaft for mounting said recording means for angular recording movements about said central axis in radial direction of said recording sheet and in a plane perpendicular to said line, said recording means sheet about the center thereof whereby recordings can be made on a standard recording sheet in a housing means having a width smaller than the diameter of the standard recording sheet.

12. Recording instrument as claimed in claim 11 including a movable member supporting said shaft for moving the same between a normal recording position, and an inoperative position in which said recording members are spaced from said recording sheet; and wherein said housing means include a movable housing part having an open position for access to said recording sheet, and a lock means for said movable housing part connected with said movable member moving said shaft to said inoperative position when said lock means is operated to open said movable housing part, and for holding said shaft in said recording position when said movable housing part is locked.

References Cited UNITED STATES PATENTS 1,760,947 6/1930 Healey 346-437 2,341,118 2/1944 Rodanet 346 X 2,903,323 9/1959 Riester et al 346-145 X 3,141,726 7/1964 Vogtlin 346-121 X 2,600,822 6/1952 Yarnall et a1 346--69 2,874,019 2/1959 Linsley et al. 34629 3,434,152 3/1969 Vogtlin 346--137 X FOREIGN PATENTS 17,226 1912 Great Britain.

JOSEPH W. HARTARY, Primary Examiner US. Cl. X.R. 346l37, 145 

